Field of the Invention
The present invention relates to a vehicle energy management device that manages a plurality of energy sources of a vehicle such as fuel energy and electrical energy.
Description of the Background Art
In an engine vehicle, an electric vehicle (EV), a hybrid electric vehicle (HEV), a fuel cell electric vehicle and the like, an energy consumption amount is suppressed by so-called sequential control of changing vehicle operation modes corresponding to information indicating a current vehicle state which is obtained from an in-vehicle sensor and the like. For example, as operation modes of the hybrid electric vehicle, there are a mode of traveling only by power of an engine, a mode of traveling only by power of a motor, a mode of traveling by using both of the power of the engine and the power of the motor, a mode of generating electricity by the power of the engine to accumulate the generated electricity in a battery or to use the generated electricity for driving the motor, and so on.
Moreover, a technology of producing a control plan (a switching plan of the operation modes) for the vehicle in consideration of not only the current vehicle state but also an estimated vehicle state in the future is under development. For example, in a case where it is estimated that the hybrid electric vehicle continuously travels uphill and downhill, efficient control becomes possible such as sufficiently charging a battery in advance before the uphill, allowing the vehicle to travel uphill by the power of the motor to increase a vacant capacity of the battery, and charging the battery with regenerative electric power obtained on the subsequent downhill.
For example, Japanese Patent Application Laid-Open No. 2001-69605 discloses a technology of calculating changes of an altitude of a traveling route of a vehicle (hybrid electric vehicle) and changes of a vehicle speed during a traveling time from a current position and traveling route of the vehicle, terrain information, a congestion degree of a road, and the like, producing a plan for regulating upper and lower limits of a state of charge (SOC) of a battery and controlling the vehicle along the plan. However, in the technology of Japanese Patent Application Laid-Open No. 2001-69605, it is difficult to highly accurately obtain an optimum controlled variable of the vehicle from map data information indicating the altitude and the terrain. Moreover, such map data and traffic information are not sufficiently detailed in some case, and further, traveling characteristics (a speed of the vehicle, a magnitude of acceleration thereof, a frequency of acceleration/deceleration thereof, a frequency of stops thereof, and the like) of the vehicle also depend on a driver, and accordingly, an error between an estimated value and an actual value of the energy consumption amount is prone to become large.
Japanese Patent No. 4918076 discloses a control device of a hybrid vehicle in order to solve this problem. In Japanese Patent No. 4918076, information of traveling characteristics when another vehicle traveled on a traveling route of an own vehicle in the past is acquired, and a control plan for the own vehicle is produced based on the information.
In a system of Japanese Patent No. 4918076, it is necessary for each of the vehicles or an external information server to hold information such as a variation of the vehicle speed and an average gradient of a road for each section on the traveling route. However, in particular, detailed information of the variation of the vehicle speed becomes enormous in terms of a data amount, and accordingly, it is considered difficult to put this system into practical use. For example, construction of a database for handling such enormous data, development of communication means for distributing the enormous data, and further, a cost required for infrastructure improvement for realizing these become large problems.
Moreover, the technology of Japanese Patent No. 4918076 is one that makes most use of the traveling (EV traveling) only by the motor, and is considered not to be capable of implementing energy optimization (for example, optimization of engine efficiency) corresponding to a purpose. Further, since the traveling characteristics of the vehicle also depend on the driver, an energy consumption amount for each section also changes depending on the driver, and is not determined uniquely. Hence, the control plan for realizing the optimization of the energy consumption on the entire traveling route differs for each individual vehicle.